The 21cm Signature of a Cosmic String Loop

Understand

Cosmic string loops lead to nonlinear baryon overdensities at early times, even before the time which in the standard LCDM model corresponds to the time of reionization.

• These overdense structures lead to signals in 21cm redshift surveys at large redshifts.
• In this paper, we calculate the amplitude and shape of the string loop-induced 21cm brightness temperature.
• We find that a string loop leads to a roughly elliptical region in redshift space with extra 21cm emission.